1. Field of the Invention
The present invention is directed to wireless personal communication devices, and in particular to a wireless communication system comprising one or more earpieces worn at the ear(s) that communicate wirelessly with a remote processing unit, or RPU, worn at the neck of a user. Such systems have application in the area of heating aids and wearable computers. The earpiece(s) and RPU may in turn communicate with other peripheral and control equipment, such as a display worn on the wrist like a watch, as well as standard public-access cellular telephone and paging systems.
2. Brief Description of the Related Art
In the prior art, U.S. Pat. No. 5,721,783 describes a hearing aid with wireless remote processor that uses reflective, or xe2x80x9cmodulated backscatter,xe2x80x9d radar technology to implement a wireless link between an RPU and one or more earpieces. In that implementation, the RPU is also described as supplying beamed power to the earpiece(s), thus reducing or eliminating the need for bulky, expensive earpiece batteries. However, the RPU described in U.S. Pat. No. 5,721,783 is intended to be xe2x80x9cworn as a wristwatch or other inconspicuous piece of jewelry, carried in a pocket or a purse, or worn on a belt over or under clothing.xe2x80x9d An RPU in the form of flat, flexible neckwear that would provide a large antenna aperture while hidden from view is not described in U.S. Pat. No. 5,721,783.
A typical form factor for the RPU of the invention described in U.S. Pat. No. 5,721,783 is a body-worn unit roughly the size of a standard PCMCIA (Personal Computer Memory Card International) Type III PC Card having 54 mm (2.13 inches) width, 85.6 mm (3.37 inches) length and 10.5 mm (0.41 inch) height. Within this volume, and at an operating frequency of 6 GHz where a quarter wavelength is 12.7 mm (0.5 inch), it is possible to place an antenna system comprising four quarter-wavelength end-fed driven elements along the width of the RPU and away from the user""s body. These driven elements may reside within a pair of elliptical quarter-cylinder cavity reflector sections (known in the art as xe2x80x9cQuarter Roundxe2x80x9d or xe2x80x9cOvoloxe2x80x9d shapes), with end reflectors, placed side-by-side and separated by a center reflector. The four driven elements, only one of which radiates at any given time, are positioned in the left or right cavity as the left or right element. Diversity switching, a technique well known in the art, is then used to establish the best choice of elements for transmitting an interrogation and receiving a reply (see, e.g., International Publication No. WO 98/44591 and its counterpart U.S. Pat. No. 5,905,473). Even with an optimum driven element choice, this antenna system is still subject to interference due to blockage from the user""s arms (also known in the art as xe2x80x9cshadowingxe2x80x9d), and may not be capable of providing an acceptably reliable communication link at all times if worn at the belt. If worn about the neck, this prior art RPU is conspicuous, and may still be subject to blockage as the user""s head turns. Furthermore, the maximum antenna aperture area available from one end of such an RPU is at most a few square centimeters (less than one square inch), which may be inadequate for many beamed-power applications. By contrast, the RPU antenna of the present invention has a comparatively large area to provide a much greater antenna aperture and gain than reflector designs used in the prior art, and is much less subject to blockage because it provides multiple driven elements distributed about the neck, where it can be worn inconspicuously.
Soft, flexible radio frequency identification (RFID) tags are well known in the art (see, e.g., U.S. Pat. No. 5,711,246). Low-cost, battery-free RFID tags that use 2.4 GHz xe2x80x9cfolded dipolexe2x80x9d printed antennas and electronic transponders embedded in flexprint (a form of flat, flexible printed circuit material well known in the art), along with beamed-power and reflective communication technology, are already in widespread use (see, e.g., xe2x80x9cRFID tags shrink and gain flexibility,xe2x80x9d EDN Magazine, Jun. 19, 1997, p. 18). Although the earpieces associated with the present invention preferably use such tag/transponder technology, the flexprint manufacturing techniques are newly, applied to the conformal necklace RPU that contains an interrogator/illuminator rather than a tag/transponder.
The types of antennas required for the necklace RPU are well known in the prior art, including electronically steered flat antenna arrays for forming the pencil beam used in beamed-power applications (U.S. Pat. No. 4,376,281) and flexible printed circuit antennas that operate at 5.8 GHz (U.S. Pat. No. 5,646,635).
Although wearable computers are well known in the prior art examples are found in U.S. Pat. Nos. 5,726,660, 5,751,260 and 5,798,733), none use an RPU in the form of a necklace.
Although many necklaces are used in body monitoring, wireless hearing aid and other audio applications, none are known to provide bi-directional communication capability between the necklace and one or more earpieces (see, e.g., U.S. Pat. Nos. 4,662,378, 5,563,951, 5,757,929, 5,793,875 and 5,818,328)
Disposable hearing aids have recently been, introduced (U.S. Pat. No. 5,881,159), but do not involve wireless technology. Wireless hearing aid and communication system earpieces known in the prior art (e.g., U.S. Pat. No. 6,021,207) are not so inexpensive as to be disposable.
It is an object of the present invention to provide a new, improved form factor for a remote processor unit (RPU) that is functionally similar to the RPU of U.S. Pat. No. 5,721,783, entitled xe2x80x9cHearing Aid with Wireless Remote Processor,xe2x80x9d issued on Feb. 24, 1998, to James C. Anderson. In the present invention, the RPU is generally in the form of a necklace, neck ribbon, neckband, neck drape, necklet, stole, collar, collar insert, bandoleer or other neckwear. This new form factor enables the manufacture of low-cost, xe2x80x9cprintablexe2x80x9d and disposable wireless hearing aids, cellular telephones, pagers and wearable computer systems.
The present invention is concerned with improvements in the RPU portion, not the earpiece portion, of a wireless personal communication system. Similar earpieces may generally be used without regard to whether the RPU is in the form of a necklace or a belt-worn unit. Size and cost reduction techniques for earpieces, resulting from the use of beamed power and reflective technologies, have already been described in U.S. Pat. No. 5,721,783, and are therefore not an object of the present invention.
It is an object of the present invention to provide numerous advantages over the traditional belt-worn RPU. Whereas RF path link losses from a belt-worn RPU may be tremendous due to body blockage (e.g., from the user""s arms and stomach) or other transmission path blockages (e.g., a table top in the path between the RPU and earpiece) the necklace approach of the present invention minimizes the probability of such obstructions. The shorter distance between necklace RPU transmitting elements and target earpieces, combined with the lower probability of obstructions, allows lower-power operation, longer battery life, reduced generation of interference to other equipment, reduced susceptibility to interference from other equipment, substantial improvement in operational reliability, and enables the use of beamed-power and reflective technologies for the associated earpieces. Although it is not required that beamed power nor reflective technologies be used in the present invention (i.e., the RPU, earpieces and other peripheral devices may all contain batteries and xe2x80x9cactivexe2x80x9d non-reflective transmitters), such technologies are preferred as they maximize the benefit of this invention in the overall system. When worn under clothing, the necklace RPU is less conspicuous than a belt-worn RPU, yet provides a considerably larger antenna aperture than would be practical with a typical belt-worn RPU in the prior art.
It is an object of the present invention to provide a xe2x80x9cprintablexe2x80x9d flexprint approach to necklace RPU fabrication, resulting in a substantial cost savings for a xe2x80x9cdisposablexe2x80x9d design, due in part to the elimination of xe2x80x9ctouch laborxe2x80x9d during manufacture (see, e.g., Stephan Ohr, xe2x80x9cTechnologists define future cellular components,xe2x80x9d Electronic Engineering Times Newspaper, Nov. 16, 1998, pp. 45-48). Although the necklace RPU could be formed from a single piece of material such as Rogers Corp. xe2x80x9cDuroidxe2x80x9d, it is preferably fabricated using flexprint material such as xe2x80x9cFlexTennaxe2x80x9d from LaBarge, Inc. When the RPU electronics are encased within the material, the entire necklace can be wiped clean with a damp cloth, or the unit can be worn inside a separate, washable cloth cover.
It is an object of the present invention that some embodiments may make use of the proximity of the necklaces with the user""s skin to perform pulse rate, temperature or resistivity measurements. A throat microphone or a variety of microphone array elements may also be added to enhance system performance. Optional secondary wirelessxe2x80x9clink circuitry may be added, along with the necessary printed antennas, to perform pager and messaging functions and cell phone functions are possible when an extra battery unit is wired to the necklace RPU.
It is an object of this invention to control system operation through the use of voice recognition and response, based directly on information contained in the user""s ambient audio environment. It is a further object of this invention to control system operation using other input devices located directly on the necklace RPU. Elastomeric pushbutton switches may be used as input devices, and al pensxe2x80x9d or xe2x80x9cfinger touchxe2x80x9d alphanumeric input devices may be used as well (see, e.g., Bruce Trunck, xe2x80x9clntegrating Digital Pens and Finger Touch,xe2x80x9d Electronic Design Magazine, Dec. 16, 1995, pp. 98-104). Another object of this invention is to control system operation using devices that are separate from the necklace RPU but communicate with the necklace via wired or wireless means. A wrist watch control panel, for example, may communicate wirelessly with the necklace RPU using reflective technology and a data format similar to that used by the earpieces, or may work using an entirely different format such as xe2x80x9cBluetoothxe2x80x9d. Similarly, a control panel in the form of a credit card size xe2x80x9cpersonal organizerxe2x80x9d can also be used.